PPC: Add MPC8XXX gpio controller

On e500 systems most SoCs implement a common GPIO controller that Linux
calls the "mpc8xxx" gpio controller. This patch adds an emulation model
for this device.

Signed-off-by: Alexander Graf <agraf@suse.de>

2 files changed, 218 insertions, 0 deletions

diff --git a/hw/gpio/Makefile.objs b/hw/gpio/Makefile.objs
index 2c8b51f..1abcf17 100644
--- a/hw/gpio/Makefile.objs
+++ b/hw/gpio/Makefile.objs
@@ -2,5 +2,6 @@ common-obj-$(CONFIG_MAX7310) += max7310.o
 common-obj-$(CONFIG_PL061) += pl061.o
 common-obj-$(CONFIG_PUV3) += puv3_gpio.o
 common-obj-$(CONFIG_ZAURUS) += zaurus.o
+common-obj-$(CONFIG_E500) += mpc8xxx.o
 
 obj-$(CONFIG_OMAP) += omap_gpio.o
diff --git a/hw/gpio/mpc8xxx.c b/hw/gpio/mpc8xxx.c
new file mode 100644
index 0000000..1aeaaaa
--- /dev/null
+++ b/hw/gpio/mpc8xxx.c
@@ -0,0 +1,217 @@
+/*
+ *  GPIO Controller for a lot of Freescale SoCs
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author: Alexander Graf, <agraf@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw/sysbus.h"
+
+#define TYPE_MPC8XXX_GPIO "mpc8xxx_gpio"
+#define MPC8XXX_GPIO(obj) OBJECT_CHECK(MPC8XXXGPIOState, (obj), TYPE_MPC8XXX_GPIO)
+
+typedef struct MPC8XXXGPIOState {
+    SysBusDevice parent_obj;
+
+    MemoryRegion iomem;
+    qemu_irq irq;
+    qemu_irq out[32];
+
+    uint32_t dir;
+    uint32_t odr;
+    uint32_t dat;
+    uint32_t ier;
+    uint32_t imr;
+    uint32_t icr;
+} MPC8XXXGPIOState;
+
+static const VMStateDescription vmstate_mpc8xxx_gpio = {
+    .name = "mpc8xxx_gpio",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(dir, MPC8XXXGPIOState),
+        VMSTATE_UINT32(odr, MPC8XXXGPIOState),
+        VMSTATE_UINT32(dat, MPC8XXXGPIOState),
+        VMSTATE_UINT32(ier, MPC8XXXGPIOState),
+        VMSTATE_UINT32(imr, MPC8XXXGPIOState),
+        VMSTATE_UINT32(icr, MPC8XXXGPIOState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void mpc8xxx_gpio_update(MPC8XXXGPIOState *s)
+{
+    qemu_set_irq(s->irq, !!(s->ier & s->imr));
+}
+
+static uint64_t mpc8xxx_gpio_read(void *opaque, hwaddr offset,
+                                  unsigned size)
+{
+    MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
+
+    if (size != 4) {
+        /* All registers are 32bit */
+        return 0;
+    }
+
+    switch (offset) {
+    case 0x0: /* Direction */
+        return s->dir;
+    case 0x4: /* Open Drain */
+        return s->odr;
+    case 0x8: /* Data */
+        return s->dat;
+    case 0xC: /* Interrupt Event */
+        return s->ier;
+    case 0x10: /* Interrupt Mask */
+        return s->imr;
+    case 0x14: /* Interrupt Control */
+        return s->icr;
+    default:
+        return 0;
+    }
+}
+
+static void mpc8xxx_write_data(MPC8XXXGPIOState *s, uint32_t new_data)
+{
+    uint32_t old_data = s->dat;
+    uint32_t diff = old_data ^ new_data;
+    int i;
+
+    for (i = 0; i < 32; i++) {
+        uint32_t mask = 0x80000000 >> i;
+        if (!(diff & mask)) {
+            continue;
+        }
+
+        if (s->dir & mask) {
+            /* Output */
+            qemu_set_irq(s->out[i], (new_data & mask) != 0);
+        }
+    }
+
+    s->dat = new_data;
+}
+
+static void mpc8xxx_gpio_write(void *opaque, hwaddr offset,
+                        uint64_t value, unsigned size)
+{
+    MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
+
+    if (size != 4) {
+        /* All registers are 32bit */
+        return;
+    }
+
+    switch (offset) {
+    case 0x0: /* Direction */
+        s->dir = value;
+        break;
+    case 0x4: /* Open Drain */
+        s->odr = value;
+        break;
+    case 0x8: /* Data */
+        mpc8xxx_write_data(s, value);
+        break;
+    case 0xC: /* Interrupt Event */
+        s->ier &= ~value;
+        break;
+    case 0x10: /* Interrupt Mask */
+        s->imr = value;
+        break;
+    case 0x14: /* Interrupt Control */
+        s->icr = value;
+        break;
+    }
+
+    mpc8xxx_gpio_update(s);
+}
+
+static void mpc8xxx_gpio_reset(MPC8XXXGPIOState *s)
+{
+    s->dir = 0;
+    s->odr = 0;
+    s->dat = 0;
+    s->ier = 0;
+    s->imr = 0;
+    s->icr = 0;
+}
+
+static void mpc8xxx_gpio_set_irq(void * opaque, int irq, int level)
+{
+    MPC8XXXGPIOState *s = (MPC8XXXGPIOState *)opaque;
+    uint32_t mask;
+
+    mask = 0x80000000 >> irq;
+    if ((s->dir & mask) == 0) {
+        uint32_t old_value = s->dat & mask;
+
+        s->dat &= ~mask;
+        if (level)
+            s->dat |= mask;
+
+        if (!(s->icr & irq) || (old_value && !level)) {
+            s->ier |= mask;
+        }
+
+        mpc8xxx_gpio_update(s);
+    }
+}
+
+static const MemoryRegionOps mpc8xxx_gpio_ops = {
+    .read = mpc8xxx_gpio_read,
+    .write = mpc8xxx_gpio_write,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+static int mpc8xxx_gpio_initfn(SysBusDevice *sbd)
+{
+    DeviceState *dev = DEVICE(sbd);
+    MPC8XXXGPIOState *s = MPC8XXX_GPIO(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &mpc8xxx_gpio_ops, s, "mpc8xxx_gpio", 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+    sysbus_init_irq(sbd, &s->irq);
+    qdev_init_gpio_in(dev, mpc8xxx_gpio_set_irq, 32);
+    qdev_init_gpio_out(dev, s->out, 32);
+    mpc8xxx_gpio_reset(s);
+    return 0;
+}
+
+static void mpc8xxx_gpio_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+
+    k->init = mpc8xxx_gpio_initfn;
+    dc->vmsd = &vmstate_mpc8xxx_gpio;
+}
+
+static const TypeInfo mpc8xxx_gpio_info = {
+    .name          = TYPE_MPC8XXX_GPIO,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(MPC8XXXGPIOState),
+    .class_init    = mpc8xxx_gpio_class_init,
+};
+
+static void mpc8xxx_gpio_register_types(void)
+{
+    type_register_static(&mpc8xxx_gpio_info);
+}
+
+type_init(mpc8xxx_gpio_register_types)